I hadn't any problems importing PDFs into Quark 5 picture boxes...until today! I don't know why this particular one didn't work because I've been using some pretty complex PDFs up to now without any problems...
I will say this, though. Even though the troublesome file opened fine in Acrobat Reader, it crashed every time I tried to print it. Also, copying it directly onto a RIP also produced an error, as did opening it in Illustrator.
In short, I suppose some PDF files aren't all that portable, and it may not be Quark at all. Then again....